U.S. patent application number 12/195330 was filed with the patent office on 2010-02-25 for arranging materials on a substrate.
This patent application is currently assigned to SEOUL NATIONAL UNIVERSITY RESEARCH & DEVELOPMENT BUSINESS FOUNDATION (SNU R&DB FOUNDATION). Invention is credited to Youngtack Shim.
Application Number | 20100047446 12/195330 |
Document ID | / |
Family ID | 41696617 |
Filed Date | 2010-02-25 |
United States Patent
Application |
20100047446 |
Kind Code |
A1 |
Shim; Youngtack |
February 25, 2010 |
ARRANGING MATERIALS ON A SUBSTRATE
Abstract
Techniques for arranging materials on a substrate are provided.
In one embodiment, a system may comprise a driver for providing a
rotational force, an outer body having an inner surface, and an
inner body having an outer surface and disposed within the outer
body in a concentric relationship therewith. The inner body may be
coupled to the driver to be rotated by the rotational force. The
system may further comprise a coupler attached to the outer body in
order to retain a substrate, which forms at least one patterned
groove therein. A fluid channel, which may be defined between the
inner and outer bodies, may be filled with a fluid medium
containing materials such as nano materials. When the inner body
rotates via the rotational force, the materials contained in the
fluid medium may be arranged in the patterned groove of the
substrate.
Inventors: |
Shim; Youngtack; (Seoul,
KR) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET, FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Assignee: |
SEOUL NATIONAL UNIVERSITY RESEARCH
& DEVELOPMENT BUSINESS FOUNDATION (SNU R&DB
FOUNDATION)
Seoul
KR
|
Family ID: |
41696617 |
Appl. No.: |
12/195330 |
Filed: |
August 20, 2008 |
Current U.S.
Class: |
427/240 ; 118/54;
977/882 |
Current CPC
Class: |
B81C 99/002 20130101;
C01B 2202/08 20130101 |
Class at
Publication: |
427/240 ; 118/54;
977/882 |
International
Class: |
B05D 1/40 20060101
B05D001/40; B05C 9/00 20060101 B05C009/00 |
Claims
1. A system for manipulating elongated nano materials included in a
fluid medium in a desired arrangement and orientation comprising: a
chamber for defining at least two opposing bodies and receiving the
fluid including the nano materials between the bodies; a driver for
rotating at least one of the bodies along a first direction and
generating a centrifugal force acting upon the nano materials in a
second direction, the second direction being at least partially
transverse to the first direction; and at least one coupler for
coupling with one of the bodies and receiving at least one
substrate defining at least one groove thereon, the coupler being
configured to dispose the groove in the arrangement and orientation
to thereby allow the nano materials in the arrangement and
orientation to enter the groove.
2. The system of claim 1, wherein the chamber defines an annular
cylinder and wherein the bodies include an inner body and an outer
body for concentrically enclosing the inner body.
3. The system of claim 2, wherein the driver is configured to
rotate at least one of the bodies.
4. The system of claim 1, wherein the fluid medium defines a finite
viscosity and wherein the nano materials are arranged and oriented
at least partially due to the centrifugal force and at least
partially due to a viscous force attributed to the viscosity.
5. The system of claim 4, wherein the nano materials are arranged
and oriented at least partially due to gravity.
6. A system, comprising: a driver for providing a rotational force;
an outer body having an inner surface; an inner body having an
outer surface disposed within the outer body in a concentric
relationship therewith and being coupled to the driver so as to be
rotated via the rotational force from the driver; at least one
substrate having at least one patterned groove formed therein; and
a coupler engaged to the outer body and being configured to retain
the substrate; wherein a fluid channel is defined between the inner
and outer bodies to accommodate a fluid medium containing
predetermined materials, and wherein the predetermined materials
are arranged in the patterned groove of the substrate when the
inner body rotates via the rotational force from the driver.
7. The system of claim 6, wherein the outer body is coupled to the
driver to be rotated via the rotational force, and wherein the
rotation of the outer body causes the predetermined materials to be
arranged in the patterned groove of the substrate.
8. The system of claim 6, further comprising a driver housing with
a top surface for enclosing the driver.
9. The system of claim 8, wherein the fluid channel is defined by
the inner surface of the outer body, the outer surface of the inner
body and the top surface of the driver housing.
10. The system of claim 8, wherein the outer body further includes
a bottom surface, and wherein the fluid channel is defined by the
inner surface of the outer body, the outer surface of the inner
body and the bottom surface of the outer body.
11. The system of claim 10, wherein a first opening is formed at
the top surface of the driver housing, and wherein a second opening
is formed at the bottom surface of the outer body.
12. The system of claim 11, wherein the driver comprises a
rotational shaft having inner and outer shafts extended through the
first opening of the driver housing.
13. The system of claim 12, wherein the inner shaft is coupled to
the inner body and the outer shaft is coupled to the outer
body.
14. The system of claim 13, further comprising a ball bearing
having inner and outer rings, wherein the ball bearing is disposed
through the second opening of the outer body.
15. The system of claim 14, wherein the inner ring is coupled to
the inner shaft and the outer ring is coupled to the outer shaft in
an air tight manner.
16. The system of claim 6, wherein the inner body is generally
shaped as a cylinder having a constant radius along a longitudinal
axis thereof.
17. The system of claim 6, wherein the inner body has a generally
tapered shape with a radius increasing or decreasing along a
longitudinal axis thereof.
18. The system of claim 6, wherein the outer body is generally
shaped as a cylinder having a constant radius along a longitudinal
axis thereof.
19. The system of claim 6, wherein the outer body has a generally
tapered shape with a radius increasing or decreasing along a
longitudinal axis thereof.
20. The system of claim 6, wherein the predetermined materials are
nano materials.
21. The system of claim 6, wherein the predetermined materials are
any one of carbon nanotubes and carbon nanowires.
22. A method of arranging materials on a substrate in a desired
pattern, comprising: forming a desired pattern on the substrate;
creating a substantially circular fluid channel; placing the
substrate in the fluid channel; filling the fluid channel with a
fluid medium containing the materials; and causing the fluid medium
to be rotated within the fluid channel to thereby arrange the
materials in the desired pattern.
23. The method of claim 22, wherein the step of causing the fluid
medium to be rotated comprises subjecting the fluid medium to a
centrifugal force and a viscous force.
24. The method of claim 23, further comprising arranging the
materials on the substrate in the desired pattern based on a vector
sum of the centrifugal and viscous forces.
25. The method of claim 23, wherein the step of causing the fluid
medium to be rotated comprises controlling a direction and a
velocity of the rotation of the fluid medium while considering the
resultant centrifugal and viscous forces.
26. The method of claim 23, wherein the step of causing the fluid
medium to be rotated comprises controlling a direction and a
velocity of the rotation of the fluid medium while considering the
centrifugal, viscous and gravitational forces.
27. The method of claim 22, wherein the materials are nano
materials.
28. The method of claim 22, wherein the materials are any one of
carbon nanotubes and carbon nanowires.
Description
BACKGROUND
[0001] One of the principal themes in the field of nanotechnology
is the development of nano materials on an atomic or molecular
scale (i.e., smaller than a micron). New or preeminent properties
of the nano materials are attributed to their nanoscale size.
Compared to macroscale materials, the materials reduced to
nanoscale display very different properties, which enable them to
be adapted for various applications. For example, an opaque
substance of macroscale may become a transparent substance of
nanoscale, a stable substance of macroscale may turn into a
combustible substance of nanoscale, a solid substance of macroscale
may be converted into a liquid substance of nanoscale at room
temperature, and an insulator of macroscale may become a conductor
of nanoscale. Due to such novel properties, the nano materials have
been widely applied in various fields.
[0002] However, despite their superior mechanical, chemical and
electrical properties, there have been significant drawbacks in
using the nano materials due to the difficulty of arranging such
small materials in a useful structure. In order to fully utilize
and apply the preeminent properties of the nano materials in
various fields, there is a need for a novel system and method which
can arrange such materials in a desired arrangement and
orientation.
SUMMARY
[0003] The present disclosure provides techniques for arranging
nano materials on a substrate. In some embodiments, a system may
comprise a driver for providing a rotational (or centrifugal)
force, an outer body having a preset shape and including an inner
circumferential surface, and an inner body having a preset shape
and including an outer circumferential surface, wherein the inner
body is disposed within the outer body in a concentric relationship
therewith. Either or both of the inner and outer bodies may be
coupled to the driver and be rotated by a rotational force. The
system of the present disclosure may further comprise a coupler
attached to the inner circumferential surface of the outer body in
order to retain a substrate. The substrate may have at least one
patterned groove formed therein. A fluid channel may be defined
between the inner and outer bodies. The fluid channel may be filled
with a fluid medium containing nano materials with predetermined
shapes and sizes. When the driver rotates either or both of the
inner and outer bodies and generates the rotational force, the nano
materials which are contained in the fluid medium and aligned with
the patterned groove of the substrate may enter the groove and be
disposed therein.
[0004] In one embodiment the outer body may be coupled to the
driver and be rotated by the rotational force. The rotation of the
outer body may further facilitate the nano materials to be arranged
within the patterned groove of the substrate.
[0005] In another embodiment, the system of the present disclosure
may further comprise a driver housing for enclosing the driver. In
addition, the fluid channel may be defined by the inner
circumferential surface of the outer body, the outer
circumferential surface of the inner body, and a top surface of the
driver housing.
[0006] In another embodiment, the outer body may further include a
bottom surface. The fluid channel may be defined by the inner
circumferential surface of the outer body, the outer
circumferential surface of the inner body, and the bottom surface
of the outer body.
[0007] In another embodiment, a first opening may be formed at the
top surface of the driver housing, while a second opening may be
formed at a center of the bottom surface of the outer body.
[0008] In another embodiment, the driver may comprise a rotational
shaft having inner and outer shafts extended through the first
opening of the top surface of the driver housing.
[0009] In another embodiment, the inner shaft may be coupled to the
inner body and the outer shaft may be coupled to the outer
body.
[0010] In another embodiment, the system of the present disclosure
may also comprise a ball bearing, which has inner and outer rings,
disposed at the second opening of the bottom surface of the outer
body.
[0011] In another embodiment, the inner ring may be coupled to the
inner shaft and the outer ring may be coupled to the outer shaft,
wherein the coupling of the inner and outer rings to their
respective shafts is air tight.
[0012] In another embodiment, the inner body may be generally
shaped as a cylinder having a constant radius along its
longitudinal axis.
[0013] In another embodiment the inner body may generally have a
tapered shape, the radius of which either increases or decreases
along its longitudinal axis.
[0014] In another embodiment the outer body may be generally shaped
as a cylinder having a constant radius along its longitudinal
axis.
[0015] In another embodiment, the outer body may generally have a
tapered shape, the radius of which either increases or decreases
along its longitudinal axis.
[0016] In another embodiment, the fluid medium may include the nano
materials in a form of a solution, emulsion, suspension, slurry,
and the like.
[0017] In another embodiment, the nano materials may include carbon
nanotubes, carbon nanowires, nanotubes of other substances,
nanowires of other substances, and nano particles of carbon or
other materials.
[0018] The present disclosure also provides methods of arranging
materials on a substrate in a desired pattern. In some embodiments,
a method may comprise forming a desired pattern on a substrate,
creating a fluid channel defining a preset dimension (e.g., a
radius, a width, a depth, and the like), positioning the substrate
in the fluid channel, filling the fluid channel with a fluid medium
containing nano materials, and causing the fluid medium to be
rotated within the fluid channel to thereby arrange the nano
materials in a desired pattern.
[0019] In one embodiment the step of causing the fluid medium to be
rotated may comprise subjecting the fluid medium to a centrifugal
force and a viscous force.
[0020] In another embodiment, the method of the present disclosure
may further comprise arranging the nano materials on the substrate
in the desired pattern based on a vector sum of the centrifugal and
viscous forces.
[0021] In another embodiment, the step of causing the fluid medium
to be rotated may comprise controlling a direction and a velocity
of the rotation of the fluid medium while considering the resultant
centrifugal and viscous forces.
[0022] In another embodiment, the step of causing the fluid medium
to be rotated may comprise controlling a direction and a velocity
of the rotation of the fluid medium while considering the resultant
centrifugal and viscous forces in view of a gravitational
force.
[0023] In another embodiment, the nano materials may include any
materials of which lengths, widths or thicknesses are in a nano
scale.
[0024] In another embodiment, the predetermined materials may
include carbon nanotubes, carbon nanowires, nanotubes of other
substances, nanowires of other substances, and nano particles of
carbon or other materials carbon nanotubes or carbon nanowires.
[0025] This Summary is provided to introduce a selection of
concepts in a simplified form that are further described below in
the Detailed Description. The Summary is not intended to identify
key or essential features of the claimed subject matter, nor is it
intended to be used to limit the scope of the claimed subject
matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIGS. 1A and 1B respectively show perspective and
cross-sectional views of a system in accordance with one
embodiment.
[0027] FIGS. 2A and 2B respectively show top and enlarged partial
views of the system shown in FIGS. 1A and (1B).
[0028] FIG. 3A shows a top view of a system having a plurality of
substrates in accordance with one embodiment.
[0029] FIG. 3B shows a top view of the substrates shown in FIG.
3A.
DETAILED DESCRIPTION
[0030] In the following detailed description, reference is made to
the accompanying drawings, which form a part hereof. In the
drawings, similar symbols typically identify similar components,
unless context dictates otherwise. The illustrative embodiments
described in the detailed description, drawings, and claims are not
meant to be limiting. Other embodiments may be utilized, and other
changes may be made, without departing from the spirit or scope of
the subject matter presented here. It will be readily understood
that the components of the present disclosure, as generally
described herein, and illustrated in the Figures, may be arranged,
substituted, combined, and designed in a wide variety of different
configurations, all of which are explicitly contemplated and make
part of this disclosure.
[0031] FIGS. 1A and 1B show an illustrative embodiment of a system
for arranging nano materials on a substrate. Specifically, FIG. 1A
shows a perspective view of the system for arranging nano materials
on a substrate, while FIG. 1B shows a cross-sectional view of the
system of FIG. 1A taken along the line A-A' of FIG. 1A. As shown in
FIG. 1A, the system 100 may include a driver housing 102. The
driver housing 102 may be generally shaped as a rectangular box.
Further, the driver housing 102 may have a circular opening 112
about a center of its top surface. However, the embodiment shown in
FIGS. 1A and 1B is illustrative only and is not intended to be in
any way limiting. Accordingly, the shape of the driver housing 102
or the location of the opening 112 may change depending on various
features and/or requirements of system operation and/or nano
materials. The driver housing 102 may be made from any rigid
material which is capable of supporting a structure thereon.
[0032] The driver housing 102 may be configured to enclose a
conventional motor unit (not shown) therewithin. The motor unit
enclosed within the driver housing 102 may include at least one
conventional AC motor or DC motor respectively having a rotating
shaft adapted to generate rotation of an outer body 104 and/or
inner body 106 and a control circuit for controlling operations of
the motor. In one embodiment, the motor may be a stepping motor
which can provide an accurate angular control, although it is
contemplated herein that other types of conventional motors may be
used as well. The rotating shaft may upwardly extend through the
opening of the driver housing 102 from the motor system enclosed
within the driver housing 102. In one embodiment, the rotating
shaft may have a dual shaft structure including an outer hollow
rotating shaft 114 and an inner rotating shaft 116, where the
control circuit may allow the motor to rotate either or both of the
outer and inner bodies 104, 106.
[0033] An outer body 104 may be mounted on the top surface of the
driver housing 102. The outer body 104 may be generally shaped as a
hollow cylinder with an open top end. Further, the bottom surface
of the outer body 104 may have a circular opening 118 formed about
its center. As long as it can receive the inner rotating shaft 116,
the opening 118 of the bottom surface may be smaller than the
opening 112 of the top surface. The outer body 104 may form a
concentric relationship with the opening 112 of the top surface. In
one embodiment, the bottom surface of the outer body 104 may be
fixedly secured on the top surface of the driver housing 104.
Alternatively, the outer body 104 may be rotatably disposed above
the driver housing 102 and form a predetermined gap G from the top
surface of the driver housing 102.
[0034] In one embodiment, the outer body 104 may be operatively
coupled to the outer hollow rotating shaft 114 extended through the
opening 112 of the top surface. The rotating shaft may deliver a
rotational force from the motor system to the outer body 104 to
rotate the outer body 104 in a desired direction at a desired
linear or angular velocity. In another embodiment, a gear mechanism
(not shown), which operatively couples the motor system to the
outer body 104, may be provided between the bottom surface of the
outer body 104 and the top surface of the driver housing 102. The
gear mechanism may deliver a rotating force from the motor system
to the outer body 104.
[0035] In another embodiment, the outer body 104 may have a
double-lumen structure including a rotatable part operatively
coupled to the motor system and a fixed part connected to the top
surface of the driver housing 102. The fixed part may surround the
rotatable part so as to protect it against external damage. In
another embodiment, the outer body 104 may have a constant radius
along its longitudinal axis. Alternatively, the outer body 104 may
have a tapered shape, the radius of which either increases or
decreases along its longitudinal axis (e.g., a circular truncated
cone). The outer body 104 may be made from any rigid, semi-rigid or
soft material which is chemically inert to the fluid medium. It is
appreciated that the outer body 104 may define other shapes and
sizes as long as such a body 104 can perform various intended
functions set forth herein.
[0036] Further, an inner body 106 may be arranged on the bottom
surface of the outer body 104. The inner body 106 may be generally
shaped as a cylinder with closed top and bottom ends. In another
embodiment, however, the top end of the inner body 106 may be
opened. The bottom surface of the inner body 106 may be rotatably
disposed in a concentric relationship with the outer body 104 and
may form a predetermined gap g from the bottom surface of the outer
body 104. In one embodiment, the bottom surface of the inner body
106 may be integrally coupled to the inner rotating shaft 116
extended through the openings 112, 118. By doing so, this may allow
the inner body 106 to rotate in a desired direction at a desired
linear or angular velocity.
[0037] In one embodiment, the inner body 106 may have a constant
radius along its longitudinal axis. The radius of the inner body
106 may be smaller than that of the outer body 104. If the outer
and inner bodies 104, 106 are generally shaped as a cylinder with a
constant radius, then a gap defined between said bodies 104, 106
also has a constant width along the longitudinal direction.
Alternatively, the inner body 106 may have a tapered shape, the
radius of which either increases or decreases along its
longitudinal axis (e.g., a circular truncated cone).
[0038] In one embodiment, the inner body 106 may be shorter than
the outer body 104. Alternatively, the inner body 106 may be taller
than or equally tall as the outer body 104. The circumferential
surface of the inner body 106 may be sufficiently rough enough so
as to acquire a desired viscous friction against a fluid medium
contacting the surface, thereby creating a flow of the fluid
medium. Further, the inner body 106 may be made from any rigid,
semi-rigid or soft material which is chemically inert to the fluid
medium. It is appreciated that the inner body 106 may define other
shapes and sizes as long as such a body 106 can perform various
intended functions set forth herein.
[0039] The system 100 may further include a ball bearing structure
120 to prevent fluid leakage without obstructing the rotation of
the inner rotating shaft 116. The ball bearing structure 120 may
include inner rings 122, outer rings 124 and balls 126. The ball
bearing structure 120 may be provided at the opening of the outer
body 104 to surround the inner rotating shaft 116. The outer ring
124 of the ball bearing structure 120 may be fixedly coupled to the
circumference of the opening of the outer body 104 in an air tight
manner. The inner ring 122 of the ball bearing structure 120 may be
coupled to the inner rotating shaft 116. The balls 126 may be
coupled between the inner and outer rings 122, 124. The ball
bearing structure 120 may further include a shield for covering the
ball bearing structure 120 to prevent any leakage of fluid or other
contaminants. The shield may be made from metal, rubber, Teflon and
the like. The above-described ball bearing structure in combination
with the outer and inner bodies 104, 106 may allow a fluid channel
108, which has a preset width, to be defined between the outer and
inner bodies 104, 106.
[0040] It is noted that the motor may be incorporated in different
locations of the system as far as it can rotate either or both of
the outer and inner bodies 106, 104 in a desired direction at a
desired speed. Accordingly and in one embodiment, the motor can be
disposed lateral to the outer and/or inner bodies 106, 104 so that
it can directly contact a side of the outer and/or inner bodies
106, 104 and directly rotate such. In another embodiment, the motor
may be disposed in another location of the system which is away
from the outer and inner bodies 106, 104 but delivers rotational
force by the gear or belt.
[0041] In operation, a predetermined portion of the fluid channel
108 may be filled with a fluid medium such as water, organic or
inorganic solution, etc. The fluid medium may include nano-scale
(or micro-scale) materials which are to be arranged on the
substrates. In one embodiment, the nano-scale materials or nano
materials may be carbon nanotubes or carbon nanowires.
[0042] The fluid medium may be selected in view of numerous factors
such as physical or chemical properties of the nano materials,
lengths or curvatures of the materials, concentrations of the
materials, rotational speeds of the driver, and the like. Depending
upon chemical and physical characteristics of the nano materials,
the fluid medium is provided as a mixture in various states such
as, e.g., a solution, an emulsion, a suspension, a slurry, and the
like. In addition, a concentration of the nano materials in the
medium may also determine the status of the fluid medium. It is
appreciated, however, that the fluid medium may be provided in any
of the above states and also in any concentration, as long as the
rotation of the outer and/or inner bodies 106, 104 can generate a
velocity gradient in the fluid medium.
[0043] As shown in FIG. 1A, one or more couplers 110 are disposed
on the inner circumferential surface of the outer body 104. Each of
the couplers 110 may be configured to engage and retain at least
one substrate. In one embodiment, the couplers 110 may have one or
more concave or convex structures, which can couple to
corresponding structures provided on back surfaces of the
substrates. The couplers 110 may be spaced apart from each other by
a certain distance or angle. In another embodiment, the couplers
110 may be fixedly attached to the inner circumferential surface of
the outer body 114. Alternatively, the couplers 110 may be movably
attached in order to retain the substrates in various positions or
angles. It should be noted that the couplers 110 may be disposed on
any location facing the fluid channel 108 as long as they can
couple to and releasably retain the substrate.
[0044] FIGS. 2A and 2B respectively show an illustrative embodiment
of top and enlarged partial views of the system shown in FIG. 1A.
Specifically, FIG. 2A shows centrifugal and viscous forces exerted
on the fluid medium flowing in the fluid channel 108 as well as
nano materials included therein when the inner body 106 rotates in
a counter-clockwise direction. Further, FIG. 2B shows a
relationship centrifugal, viscous, and gravitational forces exerted
on the fluid medium flowing in the fluid channel 108 as well as the
nano material included therein. As shown in FIG. 2A, the fluid
medium may flow in the fluid channel 108 in a counter-clockwise
direction while the inner body 106 rotates in the same
direction.
[0045] Various forces may be applied upon the fluid medium as well
as the nano materials. First a centrifugal force denoted by Fc may
be generated by the rotational movement of the inner body 106. The
centrifugal force may push the fluid medium and nano materials
toward the outer body 104. The magnitude of the centrifugal force
Fc may be proportional to the rotational speed of the inner body
106, the dynamic or kinematic viscosity of the fluid medium, the
mass of the nano material, etc. Because the fluid medium is viscous
per se, any momentum associated with the rotational movement of the
inner body 106 is gradually transferred to the fluid medium from
the outer surface of the inner body 106 to the inner surface of the
outer body 104. Therefore, the magnitude of the centrifugal force
Fc generated at each location within the fluid medium may typically
be inversely proportional to a distance measured from the center of
the rotation to the respective location. Thus, when the inner body
106 rotates, the magnitude of the centrifugal force Fc generated
near the surface of the inner body 106 may be greater than the
magnitude of the centrifugal force Fc generated near the inner
surface of the outer body 104.
[0046] As the inner body 106 rotates, the fluid medium may flow
along the fluid channel 108 as a laminar flow. A boundary layer may
be formed near the surface of the inner body 106 contacting the
fluid medium. Due to the laminar flow, the momentum from the
boundary layer, which is closer to the inner body 106, may be
transferred to an adjacent fluid layer toward the outer body 104.
Thus, the fluid medium may be affected by a viscous force Fv
exerted by the surface of the inner body 106. The viscous force may
propagate from the boundary layer toward the outer body 104. The
nano materials included in the fluid medium may be aligned along
stream lines of the fluid medium affected by the viscous force Fv
and such alignment is more prominent with the nano materials such
as carbon nanotubes which define elongated shapes. In this regard,
it should be noted that the centrifugal force Fc may act in a
radial direction, while the viscous force Fv may act in a
circumferential direction which is substantially perpendicular to
the direction of the centrifugal force Fc.
[0047] Further, when the inner body 106 rotates, the magnitude of
the viscous force Fv generated at the boundary layer, which is near
the surface of the inner body 106, may be greater than the
magnitude of the viscous force Fv generated near the outer body
104. In addition, as shown in FIG. 2B, the fluid medium flowing in
the fluid channel 108 may be farther affected by a gravitational
force Fg. The gravitational force Fg may urge the fluid medium and
the nano materials contained therein in a downward direction.
[0048] As described above, the nano materials in the fluid medium
may be affected by the centrifugal force Fc, the viscous force Fv
and the gravitational force Fg. Thus, a moving trajectory and a
velocity profile of the fluid medium may be determined by a vector
sum of said forces. In one embodiment where the motor in the driver
housing 102 rotates the inner body 106 in the clockwise or
counter-clockwise direction while the outer body 104 remains
stationary, the fluid medium as well as the nano materials included
therein may develop a velocity profile attaining its maximum value
at the outer surface of the inner body 106, decreasing therefrom
toward the outer body 104, and reaching the minimum value (i.e., 0
when no slip condition holds) at the inner surface of the outer
body 104. In another embodiment where the motor rotates only the
outer body 104 either in the clockwise or counter-clockwise
direction while the inner body 106 remains stationary, the fluid
medium as well as the nano materials may develop a velocity profile
attaining its maximum value at the inner surface of the outer body
104, decreasing therefrom toward the inner body 106, and reaching
the minimum value at the outer surface of the inner body 106. The
motor can also rotate the outer and inner bodies 104, 106 at the
same time in opposite directions, although it is feasible to rotate
such 104, 106 in the same direction but at different angular
velocity. Regardless of the rotation directions and selection of
which body to rotate, the fluid medium and nano materials then
begin to rotate around the inner body 206 and become subject to the
centrifugal force.
[0049] In operation, an operator may manipulate the trajectory and
velocity of the fluid medium and the nano materials contained
therein by varying the magnitudes of the centrifugal force Fc,
where the viscous force Fv is decided by the dynamic viscosity of
the fluid and where the gravitational force depends on the mass (or
density) of the fluid medium and nano materials. When Fc is greater
than Fv and Fg, the fluid medium and the nano materials may travel
to the outer body 104 in a trajectory substantially horizontal to
the ground and substantially normal to the inner body 106. When Fv
is significantly greater than Fc and Fg, the fluid medium and the
nano materials may travel toward the outer body 104 in a trajectory
winding the inner body 106. When Fc and Fv are significantly less
than Fg, the fluid medium and the nano materials may tend to fall
vertically to a bottom of the channel. Therefore, an operator can
obtain a desirable trajectory of the nano materials by various
means such as, e.g., manipulating operation parameters such as a
speed of rotation, a gap between the outer and inner bodies 104,
106, and the like, selecting the fluid medium as well as nano
materials each having desired material properties such as dynamic
viscosities, densities, kinematic viscosities, and the like.
[0050] FIGS. 3A and 3B respectively show an illustrative embodiment
of a system in which a plurality of substrates are mounted on
couplers of an outer body of the system and exemplary surface
patterns of said substrates. Specifically, as shown in FIG. 3A,
substrates 302 may be circumferentially mounted on the couplers 110
in a radial direction or at an acute angle with respect to the
radial direction. However, although the substrates may be disposed
on the outer body 104 as shown in FIG. 3A, it should be noted
herein that the present disclosure is not limited to such an
arrangement. Accordingly, the substrates may be disposed on the
outer surface of the inner body 106, may be disposed between the
outer and inner bodies 104, 106, and the like.
[0051] FIG. 3B shows two exemplary surface patterns of the
substrates 302 disposed on the inner surface of the outer body 104.
It should be noted that the surface patterns of the substrates 302,
which are shown in FIG. 3B, are illustrative only and are not
intended to limit the scope in any way. The substrates 302 disposed
on the inner surface of the outer body 104 may have identical or
different patterns. Further, the substrates 302 may have a
generally rectangular shape. However, the substrates 302 are
certainly not limited to such shape. For example, the substrates
302 may have a generally circular or oval shape.
[0052] In one embodiment, the substrates 302 may have a desired
pattern including various grooves into which the nano materials may
be deposited. As shown in FIG. 3B, multiple grooves 308 are defined
on the substrates 302. The grooves 308 may be aligned parallel to
the top and bottom edges of the substrates 302. However, in another
embodiment, the grooves 308 may be aligned in a preset angle with
respect to the top and bottom edges of the substrates 302. The nano
materials may be deposited into the grooves on the surfaces of the
substrates when the nano materials contained in the fluid medium
are aligned with such grooves.
[0053] In operation, the inner body 106 may begin to rotate upon
being powered by the motor system provided within the driver
housing 102. As such, the nano materials flowing with the fluid
medium may collide with the surfaces of the substrates 302 disposed
on the outer body 104. The fluid medium and the nano materials
contained therein may flow from the boundary surface, which is near
the surface of the inner body 106, to the surface of the outer body
104 so as to reach the surfaces of the substrates 302. Thereafter,
the nano materials, which collide with the surfaces of the
substrates 302, may penetrate into the grooves 308 of the
substrates 302. In such a case, depending on the shape or size of
the grooves 308, the amount of nano materials entering the grooves
308 may vary. In particular, the nano materials entering the
grooves 308 are confined to those which are aligned with the
grooves 308, while the nano materials not aligned with the grooves
308 would bounce off the grooves 308. Accordingly, the system 100
allows the substrate 302 to collect the nano materials in a desired
arrangement. In addition, the nano materials which are longer than
the grooves 308 would bounce back to the fluid medium even when one
end of each of such nano materials may land into the grooves 308,
for the viscous shear would drag the remaining portions of the nano
materials out of the grooves 308. Accordingly, the system 100
allows the substrate 308 to collect not only the nano materials
aligned therewith but also the nano materials having lengths not
exceeding those of the grooves 308.
[0054] After the nano materials are deposited into the grooves, the
motor system provided within the driver housing 102 may be
deactivated. The substrates 302 may be removed either before or
after the fluid medium is dispensed from the fluid channel 108. In
one embodiment, a protection layer may be provided on the grooves
to prevent any inadvertent loss of nano materials from the grooves
308 of the substrates 302. The protection layer may include at
least one inert, conductive or semi-conductive material which is
well known in the art. In another embodiment, the substrate 302 may
be moved into a conventional fab chamber for further processing of
the nano materials.
[0055] The present disclosure provides efficient and economical
system and method for arranging nano (or micro) materials.
According to the present disclosure, the nano materials contained
in the fluid medium may travel on the surface of the substrates to
a direction slightly oblique thereto for a relatively long time.
This may also facilitate a greater amount of nano materials to be
arranged in a desired pattern on the substrates 302. According to
the present disclosure, the nano materials may be arranged on a
substrate in a desired pattern with improved efficiency and
precision by manipulating the centrifugal, viscous and
gravitational forces, which are orthogonal to each other.
[0056] In light of the present disclosure, those skilled in the art
will appreciate that the methods described herein may be
implemented in hardware, software, firmware, middleware or
combinations thereof and utilized in systems, subsystems,
components or sub-components thereof. For example, a method
implemented in software may include a computer code to perform the
operations of the method. This computer code may be stored in a
machine-readable medium, such as a processor-readable medium or a
computer program product, or transmitted as a computer data signal
embodied in a carrier wave, or a signal modulated by a carrier,
over a transmission medium or communication link. The
machine-readable medium or processor-readable medium may include
any medium capable of storing or transferring information in a form
readable and executable by a machine (e.g., by a processor, a
computer, etc.).
[0057] From the foregoing, it will be appreciated that various
embodiments of the present disclosure have been described herein
for purposes of illustration, and that various modifications may be
made without departing from the scope and spirit of the present
disclosure. Accordingly, the various embodiments disclosed herein
are not intended to be limiting, with the true scope and spirit
being indicated by the following claims.
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